Quality Acceptance Testing, or QAT, makes sure that a piece of software meets certain quality standards and customer needs before it is made public. During this step, functionality, usability, and performance are tested to make sure the software works as planned in real life. Stakeholders, such as end users, are often involved in Quality Acceptance Testing to make sure the product is ready to be used. Quality Acceptance Testing helps make sure a smooth rollout and increases customer happiness by finding any problems that are still there.